Haha, I'm the Technical Artist who implemented this effect in It Takes Two. You hit it pretty much spot-on with how I did it! It's actually a little bit spooky how similar your code is to the code in the game xD Absolutely fantastic video on the topic, easy to understand and follow without skipping much on the details. The "cube" transition was originally not intended to be used. Just me playing around with the effect, but I left the blend parameter exposed and one of the designers hooked it up to activate when you press the button. Some minor differences in the shader that might be interesting: 1. My raymarch shader uses the same mesh as the lava lamp instead of a big box. (saves on overdraw) 2. The raymarch starts at the surface of the object. (saves on march steps.) 3. I did not think to use a cone SDF to clip the spheres, you can totally see mine awkwardly clipping the edges from this sometimes. x) 4. To get lighting on the spheres, it's actually a standard "lit" material, and it returns the SDF's normal, base color, emissive, etc to be lit by the engine. Neat trick too make your SDFs look more real if you have lighting already.

Nice stuff! Another thing that can help with performance is to use the surface of the lamp glass (or a proxy surface with the same shape) as the surface to apply the SDF shader to, instead of an "SDF World" overlay - it will reduce the amount of rays to only the pixels that the surface covers. And you can also start the marches from the surface (or slightly behind them) instead of doing that from the camera :)

wait a sec. Did you just post after 3 years? NICE

YOOOOOOO its like 5am but still great to see an upload c:

From the clips in your video I'm not sure the lava lamp in It Takes Two is anywhere near as sophisticated as this one. I always love seeing creative applications of ray marching, though. Nice job

The legend returns!

Was literally just looking at your channel and hoping you'd be back soon, and here you are!

I’ve missed your videos!!

You're back!! I hope you make some more, I absolutely love your videos!

The king has returned! 🥳 fantastic as always ^^

He's back!! I'm happy your back making videos!

Glad to have you back. Your videos are very inspirational for aspiring technical artists!

some of the best technical art information in the world. thank u!!

One of the most effective explanations of ray marching I've come across on YT.

Watching raymarching always makes my brain happy

Signed Distance Fields can be generated from signed distance functions, so they are interchangable anyway.

dude thank u so much! i was recently trying sdf-s but i wasn't able to get them to work properly because i was following unity tutorials.

These videos are insanely entertaining and educational, i hope you continue making them :D

Good to see you again, I loved your snow video!

Love your videos! Glad to see you back ;)

wow, i just browsed this channel yesterday and thought if it's going to be active again any time soon... turned out to be more soon that i'd imagined great video! i think the final result is even better than in it takes two

Incredible making the whole lava from a shader, well done! Took a peek at your channel and your other videos are from 2 years ago. Hoping for some more videos like this in the nearish future, great work!

Seeing a video from you in my subscriptions made my day. It's a great one as usual, thank you!

This looks really good! I will have to play with raymarching shaders myself when I find the time for it. Thanks for making this!

so good to have you back!

Splendid video Martin. Thank you.

This (as well as your other videos) are incredibly valuable and high quality in content and production value. I'm shocked that you're not bigger on youtube, but maybe this is a very niche domain. I want you to keep making stuff and be sustainable, so putting my money where my mouth is and subscribing to your patreon later today.

insane level of quality on this one - subscribing and love the content

A very great tutorial, very well explained. Thanks for doing it !

Hope you make more videos! These are amazing.

I'm really happy to see new video from you! Master of knowledge dropping. My first solution idea was using 3D meshes + depth buffer.

new martin donald video is the biggest event in the past year

Love your videos! Im ALWAYS hype when you drop a banger of a video (which is everytime!) :)

YES YOURE BACK AAAA

It's been a while. Great to see

THE LEGEND RETURNS (thank you for your snow video btw, I'm using the approach you described for a game I'm working on atm)

Glad you're back!

I missed this video on release because it had been such a while since your last upload, but wow I really hope we see more videos because I've missed these a lot.

Nice breakdown! Can confirm it was raymarching, sent it to collegue who made it

oh im glad youre uploading again!!

Dude you back🎉

I did some work on raymarching at uni, and Inigo Quilez really was a godsend. Love that guy so much. He even demonstrated how to make it all work in 4 dimensions, which formed the backbone of the my work. I also added some stuff from soem videos codeparade has done on the subject, and added in things like glowing edges and (almost) phong shading. 10/10 rendering method

Yoooo, you are back! And you are using my favourite engine!

It's been forever, welcome back champ

It's definitely good enough for a prop, and a great excuse to talk about ray marching, but I honestly think this is a hammer creating nails situation. You're great at shaders, and ray marching is fun, so anything that can be, must be. ... But a physical simulation would do this so much better. In real life, lava lamp wax blobs don't anticipate meeting another blob and smoothly deform into them, they collide, _then_ merge, then surface tension drags them together based on their inertia, and when equalised, the momentum is shed by rippling oscillations of the new sphere. When a blob splits, it looks a bit smooth-SDFey until it gets far enough apart from itself, then the connecting strand breaks in interesting ways dictated by surface tension. If the strand is long enough, surface tension can't keep the two halves of it together enough to incorporate it entirely into the two new blobs, and you get a couple little bloblets in the middle. Again, the momentum of the strand shooping back into the parent blob causes oscillations. It goes without saying that there also aren't a defined number of blobs in a lava lamp.

oh! Nice news you are back! 😀

Thrilled to see you're making videos again! Or maybe I need to adjust my expectations for how long it takes to put these together while having a life...

Man, i thought you wouldn't upload again, i've searched everywhere else to see if you had some new content, twitter, linkedin, facebook, etc It's good to see you back. If you could make a video talking about this career and some resources that we can use it would be awesome! Congrats

yay, you're back! :)

I'm not entirely sure why I ran into that issue because I never saw it happen in the video, but in case anybody else is struggling to get the depth test to work: The calculated distance d depends entirely on the position of the camera, and is unaffected by its rotation. This is however not the case for the depth buffer. When the camera turns, the depth of some objects that are now to the edge of the view has decreased. Now, when comparing the distance of a pixel from the raymarching that is far off to the corners of the camera, it might be greater than the depth of an object closely behind, so it doesn't show. This can be fixed by calculating the depth of the raymarched pixel with this line: float z = (PROJECTION_MATRIX * VIEW_MATRIX * vec4(ro + d*rd, 1.0)).z; Now take ALPHA = step(z, min(MAX_DIST, linear_depth)) and your problem should be solved! I was trying to get the project files to verify if this error happens in the original project as well, but they weren't available yet on Pateron. :(

I know i would love your videos, subscribed

You're back ❤

Really great video! It would be really nice to see more descriptive variable names though! Having so many single or 2 character variables makes the code very hard to understand at a glance, which when going through the code quickly like you do for a video makes it easy to get lost in the explanation. Also, glad you're back!

Return of the King 🙌🙌🙏

Welcome back

Loved watching this video! Fragment shader coding is a fantastic hobby of mine. Another way to render an SDF is to use Marching Cubes. Could definitely be something you might like, as you can reduce the quality and still get a good result, rather than a low Res version with Ray Marching. You might like having a look at that, given your background in vertex shaders!

Man I was expecting you to say '' ripping the games code'' at :41 lmao nice code i've been kinda miffed at some of the lava lamps I've seen in other games (take like Stray for example, they appear frequently but just use a moving gif / texture atlas for the effect) Or in other games where they use a particle engine. This looks cleaner and I like the effect better. Thanks for the code :)))))

Awesome video

The king is back! I'd never normally ask another KZfaqr to post more often given how much effort it is, but 2 years is 2 long ^^

great video ! you did a really good job breaking down the steps, as well as expanding on the methodology that is often documented for fx like this. The only critique is variable naming. In the shader-programming/shadertoy world, there's this weird code-golf-like tendency to have very very short variable names to describe things. This is fine when you're making demo scenes that need to fit into very small files, but for tutorials/education and documentation it would be very helpful to use actual names for variables instead of abbreviations. For example, defining `ray_origin` and `ray_distance` instead of `ro` and `rd` immediately provides necessary context when reviewing the source code. Keep up the good work, I'm really loving the videos you're making and the topics you're covering !

This is super cool

Fantastic 💙

He returns!

NEW VIDEO LESGO

thanks for this video, it really saved my a*s for a prototype assignment :)

oh yeeeeeeeee

Awesome!

Cool video! I hope, next one won't take another two years 😳

nice, just did water shader using this. Will use it for parallax occluded grass in a pixel art style 3d game!

The lava is likely just some signed distance function blobs moving up/down, so that you get a metaballs effect, and they're just raymarching that.

Hope you a healthy, wealthy, happy life

I was looking for a way to use rasterized depth with raymarching for a while back when I was working on my own thing, but it turns out there's an implementation in Godot's documentation of all places?

Wow I've just made a lava lamp myself. ^^ But it's actually based on metaballs, so i think it costs a bit less performance. It obviously does not hold up as good as yours up close, but it does not have to. ^^

awsome

The smooth minimum is pretty easy to understand: The normal one goes AAAABBBB due to the 'if' switching abruptly between the two. To make it smooth, you detect the corner (A and B closer than K) then you go AASSSBB, where S is how you want your corner to look like from A+k=B to A=k+B If I remember correctly, the one in the video was a parabola, but you can pick a sin or whatever other funky transition you want.

Unreal engine 5 & Godot 4 really amazing Engine's.

Im trying to implement raymarching as the main thing in my game using Godot, and im running into issues when using Mod to try to loop space, and also, objects appear bugged in various ways when applying other transformations on them

Im really glad you are back. I really mean it. Having said that, i know its unrelated but i wasnt given any help and im really desperate. I have an offtopic question regarding VAT: Im using a character mesh which is uses an armature. This will lead to complications once there is bovemovent/rotations . Is there a way to ignore the bone movement while baking the VAT?

Isn't the function and the field just two sides of the same thing, the function returns the value at a given coordinate in the field?

To improve performance, instead of using separate spheres and roundboxes, use just the roundboxes and change the roundness parameter until they become a sphere! This way you avoid marching and having to union 4 extra shapes that might never even be used!

How in the does this SDF work? If it has to loop over every object in the scene and check the distance to each based in the distance to the center of each and its rotation and what shape it itself is then this is no more efficient than normal collision detection. Maybe efficiency is not the point, but accuracy?

Your version actually looks way better in my opinion

Great video.. but man, people who use 1 or 2 digit variable names are a different kind of chaotic haha

The Art of Code

Hey, I would love to play with this code. Is there any chance of you publishing your work?

I'm new to godot and maybe I missed something but I cannot figure out how the GRADIENT portion works at the end of the video. Is this a separate node I need to create myself and somehow plug into this shader? Thank you for the video, it was fun to follow along

Isn’t a signed distance field basically the same as a signed distance function, just in 2D and baked into a texture?

I find it funny your mentioned the difference between sdfs and sdfs at the start if you would have released this video 2 years ago if would have saved an argument or two for me haha. Im not a low level guy in any way but could you tell me what this was written with? Its prolly a fairly fast language if your sending out all those rays.

I'm confused as to your statement that signed distance fields are different from signed distance functions. Your function is in `R^n -> R`, which is no different from a n-dimensional scalar field. Is there a semantical difference I'm missing there?

Fun Fact: Lava Lamps actually give true randomness, because it is unknown, how and when the Bubbles will appear

Fellow mate which also uses single letter variable names 🤣

If the ray marches back in time as it marches in space (finite speed of light you know) one gets a relativistic raymarcher: kzfaq.info/get/bejne/f95hi8-pq5yaip8.html

Sir, a function over a space is a field, is the same thing

well an sdf is and sdf that was saved into an array lol

It would be fantastic if you could create a video tutorial on how to craft game physics akin to the ones in this Mercury game (kzfaq.info/get/bejne/nqydaMyotK2unJs.html) using Godot 4.x. 🎮 The physics depicted have a whimsical similarity to the flow of a lava lamp, yet with a heightened level of sophistication. 🌋 Your expertise showcased through a tutorial could be immensely valuable and enlightening. Thank you! 🙏

I've missed you bby!

Hi Martin, I really love your videos and they're so insightful ❤️! I'm a beginner tech artist at the very start of my journey and I don't think I've heard about raymarching until now 😅 I guess my question would be: how do you even begin to look for a solution to something like this, if you wouldn't have known about the concept? And if it's supposed to be common knowledge for a TA.. can you recommend any resources on sort of "here's what you should know about this topic" kind of way? (At least to mention the subjects, i guess it's easier to dig then if you know what you're looking for) Or how do you learn new stuff as a TA? It feels like there's so much out there it's confusing to know where to start 🥲